Add HTTP-specific metrics for password forms

components/password_manager/core/browser/password_form_manager.h

Index: components/password_manager/core/browser/password_form_manager.h
diff --git a/components/password_manager/core/browser/password_form_manager.h b/components/password_manager/core/browser/password_form_manager.h
index 7b312eb45024bce65daddc5bb9a505d7068cc507..d8e5e296ee5dc79d0123979d894b4da619b86585 100644
--- a/components/password_manager/core/browser/password_form_manager.h
+++ b/components/password_manager/core/browser/password_form_manager.h
@@ -561,6 +561,10 @@ class PasswordFormManager : public FormFetcher::Consumer {
   // FormFetcher instance which owns the login data from PasswordStore.
   FormFetcher* const form_fetcher_;
 
+  // True if the main frame's visible URL, at the time this PasswordFormManager
+  // was created, is secure.
+  bool is_main_frame_secure_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(PasswordFormManager);
 };